Implemented file reading

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@4157 a95241bf-73f2-0310-859d-f6bbb57e9c96
2003-07-31 06:59:21 +00:00
parent 928e05006d
commit 3dc4d42634
2 changed files with 346 additions and 16 deletions
@@ -1,5 +1,6 @@
 #include "Icb.h"

+#include "AllocationDescriptorList.h"
 #include "DirectoryIterator.h"
 #include "Utils.h"
 #include "Volume.h"
@@ -7,22 +8,24 @@
 using namespace Udf;

 Icb::Icb(Volume *volume, udf_long_address address)
-	: fVolume(NULL)
-	, fIcbData(volume ? volume->BlockSize() : 0)
+	: fVolume(volume)
+	, fData(volume)
 	, fInitStatus(B_NO_INIT)
 	, fId(to_vnode_id(address))
+	, fFileEntry(&fData)
+	, fExtendedEntry(&fData)
 {
-	DEBUG_INIT_ETC(CF_PUBLIC, "Icb", ("Volume*(%p), long_address(block: %ld, partition: %d, length: %ld)", volume, address.block(), address.partition(), address.length()));  
+	DEBUG_INIT_ETC(CF_PUBLIC, "Icb", ("volume: %p, address(block: %ld, "
+	               "partition: %d, length: %ld)", volume, address.block(),
+	               address.partition(), address.length()));  
 	status_t err = volume ? B_OK : B_BAD_VALUE;
 	if (!err) {
-		err = fIcbData.InitCheck();
+		off_t block;
+		err = fVolume->MapBlock(address, &block);
 		if (!err) {
-			err = volume->Read(address, fIcbData.Size(), fIcbData.Data());
-			if (!err) {
-				udf_icb_header *header = reinterpret_cast<udf_icb_header*>(fIcbData.Data());
-				PDUMP(header);
-				err = header->tag().init_check(address.block());
-			}
+			udf_icb_header *header = reinterpret_cast<udf_icb_header*>(fData.SetTo(block));
+			PDUMP(header);
+			err = header->tag().init_check(address.block());
 		}
 	}		
 	fInitStatus = err;
@@ -34,6 +37,51 @@ Icb::InitCheck()
 	return fInitStatus;
 }

+status_t
+Icb::Read(off_t pos, void *buffer, size_t *length, uint32 *block)
+{
+	DEBUG_INIT_ETC(CF_PUBLIC | CF_HIGH_VOLUME, "Icb",
+	               ("pos: %lld, buffer: %p, length: (%p)->%ld", pos, buffer, length, (length ? *length : 0)));
+
+	if (!buffer || !length || uint64(pos) >= Length())
+		RETURN(B_BAD_VALUE);
+
+	switch (IcbTag().descriptor_flags()) {
+		case ICB_DESCRIPTOR_TYPE_SHORT: {
+			PRINT(("descriptor type: short\n"));
+			AllocationDescriptorList<ShortDescriptorAccessor> list(this, ShortDescriptorAccessor(0));
+			RETURN(_Read(list, pos, buffer, length, block));
+			break;
+		}
+	
+		case ICB_DESCRIPTOR_TYPE_LONG: {
+			PRINT(("descriptor type: long\n"));
+			AllocationDescriptorList<LongDescriptorAccessor> list(this);
+			RETURN(_Read(list, pos, buffer, length, block));
+			break;
+		}
+		
+		case ICB_DESCRIPTOR_TYPE_EXTENDED: {
+			PRINT(("descriptor type: extended\n"));
+//			AllocationDescriptorList<ExtendedDescriptorAccessor> list(this, ExtendedDescriptorAccessor(0));
+//			RETURN(_Read(list, pos, buffer, length, block));
+			RETURN(B_ERROR);
+			break;
+		}
+		
+		case ICB_DESCRIPTOR_TYPE_EMBEDDED: {
+			PRINT(("descriptor type: embedded\n"));
+			RETURN(B_ERROR);
+			break;
+		}
+		
+		default:
+			PRINT(("Invalid icb descriptor flags! (flags = %d)\n", IcbTag().descriptor_flags()));
+			RETURN(B_BAD_VALUE);
+			break;		
+	}
+}
+
 status_t
 Icb::GetDirectoryIterator(DirectoryIterator **iterator)
 {
@@ -51,4 +99,37 @@ Icb::GetDirectoryIterator(DirectoryIterator **iterator)
 	return err;
 }

+status_t
+Icb::Find(const char *filename, vnode_id *id)
+{
+	DEBUG_INIT_ETC(CF_PUBLIC | CF_DIRECTORY_OPS | CF_HIGH_VOLUME, "Icb",
+	               ("filename: `%s', id: %p", filename, id));
 	               
+	if (!filename || !id)
+		RETURN(B_BAD_VALUE);
+		
+	DirectoryIterator *i;
+	status_t err = GetDirectoryIterator(&i);
+	if (!err) {
+		vnode_id entryId;
+		uint32 length = B_FILE_NAME_LENGTH;
+		char name[B_FILE_NAME_LENGTH];
+		
+		bool foundIt = false;
+		while (i->GetNextEntry(name, &length, &entryId) == B_OK)
+		{
+	    	if (strcmp(filename, name) == 0) {
+	    		foundIt = true;
+	    		break;
+	    	}	
+		}
+		
+		if (foundIt) {
+			*id = entryId;
+		} else {
+			err = B_ENTRY_NOT_FOUND;
+		}
+	}
+	
+	RETURN(err);
+}
@@ -21,8 +21,8 @@ extern "C" {
 #include "cpp.h"
 #include "UdfDebug.h"

+#include "CachedBlock.h"
 #include "DiskStructures.h"
-#include "MemoryChunk.h"
 #include "SinglyLinkedList.h"

 namespace Udf {
@@ -30,6 +30,36 @@ namespace Udf {
 class DirectoryIterator;
 class Volume;

+/*! \brief Abstract interface to file entry structure members
+	that are not commonly accessible through udf_file_icb_entry().
+	
+	This is necessary, since we can't use virtual functions in
+	the disk structure structs themselves, since we generally
+	don't create disk structure objects by calling new, but
+	rather just cast a chunk of memory read off disk to be
+	a pointer to the struct of interest (which works fine
+	for regular functions, but fails miserably for virtuals
+	due to the vtable not being setup properly).
+*/
+class AbstractFileEntry {
+public:
+	virtual uint8* AllocationDescriptors() = 0;
+	virtual uint32 AllocationDescriptorsLength() = 0;
+};
+
+template <class Descriptor>
+class FileEntry : public AbstractFileEntry {
+public:
+	FileEntry(CachedBlock *descriptorBlock = NULL);
+	void SetTo(CachedBlock *descriptorBlock);
+	virtual uint8* AllocationDescriptors();
+	virtual uint32 AllocationDescriptorsLength();
+private:
+	Descriptor* _Descriptor();
+	
+	CachedBlock *fDescriptorBlock;
+};
+
 class Icb {
 public:
 	Icb(Volume *volume, udf_long_address address);
@@ -42,24 +72,243 @@ public:
 	bool IsDirectory() { return InitCheck() == B_OK
 	                     && (Type() == ICB_TYPE_DIRECTORY || Type() == ICB_TYPE_STREAM_DIRECTORY); }
 	
-	// directories
+	uint32 Uid() { return 0; }//FileEntry()->uid(); }
+	uint32 Gid() { return 0; }
+	uint16 FileLinkCount() { return FileEntry()->file_link_count(); }
+	uint64 Length() { return FileEntry()->information_length(); }
+	mode_t Mode() { return (IsDirectory() ? S_IFDIR : S_IFREG) | S_IRUSR | S_IRGRP | S_IROTH; }
+	
+	uint8 *AllocationDescriptors() { return AbstractEntry()->AllocationDescriptors(); }
+	uint32 AllocationDescriptorsSize() { return AbstractEntry()->AllocationDescriptorsLength(); }
+	
+	status_t Read(off_t pos, void *buffer, size_t *length, uint32 *block = NULL);
+	
+	// for directories only
 	status_t GetDirectoryIterator(DirectoryIterator **iterator);
+	status_t Find(const char *filename, vnode_id *id);
+	
+	Volume* GetVolume() const { return fVolume; }
 	
 private:
 	Icb();	// unimplemented
 		
-	udf_icb_entry_tag& IcbTag() { return (reinterpret_cast<udf_icb_header*>(fIcbData.Data()))->icb_tag(); }
+	udf_tag& Tag() { return (reinterpret_cast<udf_icb_header*>(fData.Block()))->tag(); }
+	udf_icb_entry_tag& IcbTag() { return (reinterpret_cast<udf_icb_header*>(fData.Block()))->icb_tag(); }
+	AbstractFileEntry* AbstractEntry() {
+		DEBUG_INIT(CF_PRIVATE | CF_HIGH_VOLUME, "Icb");
+		return (Tag().id() == TAGID_EXTENDED_FILE_ENTRY)
+//	             ? reinterpret_cast<udf_extended_file_icb_entry*>(fData.Block())
+//	             : reinterpret_cast<udf_file_icb_entry*>(fData.Block()));
+	             ? &fExtendedEntry
+	             : &fFileEntry;
+	}
+	udf_file_icb_entry* FileEntry() { return (reinterpret_cast<udf_file_icb_entry*>(fData.Block())); }
+	udf_extended_file_icb_entry& ExtendedEntry() { return *(reinterpret_cast<udf_extended_file_icb_entry*>(fData.Block())); }

+	template <class DescriptorList>
+	status_t _Read(DescriptorList &list, off_t pos, void *buffer, size_t *length, uint32 *block);

 	
 private:
 	Volume *fVolume;
-	MemoryChunk fIcbData;
+	CachedBlock fData;
 	status_t fInitStatus;
 	vnode_id fId;
 	SinglyLinkedList<Strategy::SinglyLinkedList::Auto<DirectoryIterator*> > fIteratorList;
+	FileEntry<udf_file_icb_entry> fFileEntry;
+	FileEntry<udf_extended_file_icb_entry> fExtendedEntry;	
 };

+/*! \brief Does the dirty work of reading using the given DescriptorList object
+	to access the allocation descriptors properly.
+*/
+template <class DescriptorList>
+status_t
+Icb::_Read(DescriptorList &list, off_t pos, void *_buffer, size_t *length, uint32 *block)
+{
+	DEBUG_INIT_ETC(CF_PRIVATE | CF_HIGH_VOLUME, "Icb", ("list: %p, pos: %lld, buffer: %p, length: (%p)->%ld",
+	               &list, pos, _buffer, length, (length ? *length : 0))); 
+	if (!_buffer || !length)
+		RETURN(B_BAD_VALUE);
+		
+	uint64 bytesLeftInFile = uint64(pos) > Length() ? 0 : Length() - pos;
+	size_t bytesLeft = (*length >= bytesLeftInFile) ? bytesLeftInFile : *length;
+	size_t bytesRead = 0;
+	
+	Volume *volume = GetVolume();		
+	status_t err = B_OK;		
+	uint8 *buffer = reinterpret_cast<uint8*>(_buffer);
+	bool isFirstBlock = true;
+	
+	while (bytesLeft > 0 && !err) {
+		
+		PRINT(("pos: %lld\n", pos));
+		PRINT(("bytesLeft: %ld\n", bytesLeft));
+		
+		udf_long_address extent;
+		bool isEmpty = false;
+		err = list.FindExtent(pos, &extent, &isEmpty);
+		if (!err) {
+			PRINT(("found extent for offset %lld: (block: %ld, partition: %d, length: %ld, type: %d)\n",
+			       pos, extent.block(), extent.partition(), extent.length(), extent.type()));
+			       
+			switch (extent.type()) {
+				case EXTENT_TYPE_RECORDED:
+					isEmpty = false;
+					break;
+				
+				case EXTENT_TYPE_ALLOCATED:
+				case EXTENT_TYPE_UNALLOCATED:
+					isEmpty = true;
+					break;
+				
+				default:
+					PRINT(("Invalid extent type found: %d\n", extent.type()));
+					err = B_ERROR;
+					break;			
+			}
+			
+			if (!err) {
+				// Note the unmapped first block of the total read in
+				// the block output parameter if provided
+				if (isFirstBlock) {
+					isFirstBlock = false;
+					if (block)
+						*block = extent.block();
+				}
+							
+				off_t blockOffset = pos - off_t((pos >> volume->BlockShift()) << volume->BlockShift());
+				size_t fullBlocksLeft = bytesLeft >> volume->BlockShift();
+				
+				if (fullBlocksLeft > 0 && blockOffset == 0) {
+					PRINT(("reading full block (or more)\n"));				
+					// Block aligned and at least one full block left. Read in using
+					// cached_read() calls.
+					off_t diskBlock;
+					err = volume->MapBlock(extent, &diskBlock);
+					if (!err) {
+						size_t fullBlockBytesLeft = fullBlocksLeft << volume->BlockShift();
+						size_t readLength = fullBlockBytesLeft < extent.length()
+						                      ? fullBlockBytesLeft
+						                      : extent.length();					
+					
+						if (isEmpty) {
+							PRINT(("reading %ld empty bytes as zeros\n", readLength));
+							memset(buffer, 0, readLength);
+						} else {
+							off_t diskBlock;
+							err = volume->MapBlock(extent, &diskBlock);
+							if (!err) {							
+								PRINT(("reading %ld bytes from disk block %lld using cached_read()\n",
+								       readLength, diskBlock));
+								err = cached_read(volume->Device(), diskBlock, buffer,
+								                  readLength >> volume->BlockShift(),
+								                  volume->BlockSize());
+							} 
+						}
+						
+						if (!err) {
+							bytesLeft -= readLength;
+							bytesRead += readLength;
+							pos += readLength;
+							buffer += readLength;
+						}					
+					}
+					
+				} else {
+					PRINT(("partial block\n"));
+					off_t partialOffset;
+					size_t partialLength;
+					if (blockOffset == 0) {
+						// Block aligned, but only a partial block's worth remaining. Read
+						// in remaining bytes of file
+						partialOffset = 0;
+						partialLength = bytesLeft;
+					} else {
+						// Not block aligned, so just read up to the next block boundary.
+						partialOffset = blockOffset;
+						partialLength = volume->BlockSize() - blockOffset;
+						if (bytesLeft < partialLength)
+							partialLength = bytesLeft;
+					}					
+					
+					PRINT(("partialOffset: %lld\n", partialOffset));
+					PRINT(("partialLength: %ld\n", partialLength));
+					
+					if (isEmpty) {
+						PRINT(("reading %ld empty bytes as zeros\n", partialLength));
+						memset(buffer, 0, partialLength);						
+					} else {
+						off_t diskBlock;
+						err = volume->MapBlock(extent, &diskBlock);
+						if (!err) {
+							PRINT(("reading %ld bytes from disk block %lld using get_block()\n",
+							       partialLength, diskBlock));
+							uint8 *data = (uint8*)get_block(volume->Device(), diskBlock, volume->BlockSize());
+							err = data ? B_OK : B_BAD_DATA;
+							if (!err) {
+								memcpy(buffer, data+partialOffset, partialLength);
+								release_block(volume->Device(), diskBlock);
+							}
+						}
+					}
+					
+					if (!err) {
+						bytesLeft -= partialLength;
+						bytesRead += partialLength;
+						pos += partialLength;
+						buffer += partialLength;
+					}					
+				}				 
+			}
+		} else {
+			PRINT(("error finding extent for offset %lld: 0x%lx, `%s'", pos,
+			       err, strerror(err)));
+			break;
+		}
+	}
+	
+	*length = bytesRead;
+	
+	RETURN(err);
+}
+
+template <class Descriptor>
+FileEntry<Descriptor>::FileEntry(CachedBlock *descriptorBlock)
+	: fDescriptorBlock(descriptorBlock)
+{
+}
+
+template <class Descriptor>
+void
+FileEntry<Descriptor>::SetTo(CachedBlock *descriptorBlock)
+{
+	fDescriptorBlock = descriptorBlock;
+}
+
+template <class Descriptor>
+uint8*
+FileEntry<Descriptor>::AllocationDescriptors()
+{
+	Descriptor* descriptor = _Descriptor();
+	return descriptor ? descriptor->allocation_descriptors() : NULL;
+}
+
+template <class Descriptor>
+uint32
+FileEntry<Descriptor>::AllocationDescriptorsLength()
+{
+	Descriptor* descriptor = _Descriptor();
+	return descriptor ? descriptor->allocation_descriptors_length() : 0;
+}
+
+template <class Descriptor>
+Descriptor*
+FileEntry<Descriptor>::_Descriptor()
+{
+	return fDescriptorBlock ? reinterpret_cast<Descriptor*>(fDescriptorBlock->Block()) : NULL;
+}
+
 };	// namespace Udf

 #endif	// _UDF_ICB_H